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Much has been made of the intermittent fasting eating plan that has gained popularity in recent years. A basic internet search will reveal dozens, if not hundreds of articles on the subject, as well as success stories of those who have followed it.

While there are many sides to the intermittent fasting story, at least according to experts, it has been generally agreed that it can be helpful for some athletes. This includes bodybuilders who have long adhered to an eating plan that involves eating several meals a day. However, what about runners who are looking to enhance their performance? Let’s look at some of the facts surrounding it.

What is intermittent fasting?

Simply put, intermittent fasting is what its name suggests, periods of fasting mixed with periods of non-fasting. However, most experts and those who practice it, insist that it's not a diet. Instead, they claim it is a pattern of eating where you schedule your meals to get the most out of them.

Available information even goes as far to suggest that your caloric intake during intermittent fasting, won't be much different from your caloric intake before you started, if at all. It's not 'cutting calories', as in many diets, but consuming your calories only during certain times of the day.

It's also known for its simplicity in that it fits easily into the busy schedule and lives of people. Swedish trainer and nutrition expert Martin Berkhan, creator of LeanGains began intermittent fasting in the last decade after growing tired of the painstaking obsession with more traditional meal plans.

How does it work?

Again, intermittent fasting doesn't mean cutting calories, but consuming all of your nutrients during your eating period. Studies have shown that when you are in the 'fed' state after a meal, it's hard for your body to burn fat because insulin levels are high.

After your body has digested and absorbed the food you ate, it enters into a post-absorptive state, which lasts for eight to 12 hours after the meal. Your body then enters into fasting state where it’s much easier for it to burn fat because your insulin levels are low.

For many people, their body is rarely in that fat-burning state that results from fasting because they don't go that long between meals. Intermittent fasting allows you to lose fat without changing what you eat or how much.

Benefits of intermittent fasting

Studies, and the experiences of those who have tried intermittent fasting for an extended period, suggest that there is a variety of benefits for those who practice an intermittent fasting plan:

Simplicity. As Berkhan noted in his own personal experience, intermittent fasting frees one from obsessive meal planning and preparation. Even with one less meal a day that stress is eased.

Increased oxygen use. A recent study showed that men who worked out after an overnight fast had improvements in the ability to use oxygen and energy stores in the muscles.

Improved Health. Intermittent fasting has been shown to improve the body's immune system, while also controlling the glycemic load and insulin response in the body.

What to be aware of on this plan

Critics of intermittent fasting cite a variety of worrisome issues, including the fact that it may cause people to overeat. This may occur in intermittent fasting regimens where days of fasting and non-fasting are alternated. Some scientific research has also shown that fasting actually decreases athletic performance.

For example, studies on Muslim athletes showed significant decreases in athletic efficiency during the fasting periods of Ramadan. Many experts say meals in close proximity are essential for optimal workout performance.

Intermittent fasting eating plans

If you decide that intermittent fasting is worth trying, here are some plans you can try:

LeanGains. In this method, fasting occurs for 16 hours (from 10 p.m. to 2 p.m.), while food consumption occurs in three meals during an eight-hour window.

Periodic Fast. This entails a fast of 24 hours, starting at any time of the day, usually not more than one or two times a week.

Warrior Diet. The Warrior Diet promotes one healthy meal a day, typically at dinner. The plan claims to be in sync with the body's circadian rhythm and to remove harmful toxins from the body.

Alternate Day Fasting. Similar to a periodic fast, this involves food consumption over a 24-hour period followed by 24 hours of fasting with water only for every two-day cycle.

Keep in mind, intermittent fasting is not recommended for:

Pregnant women

Women who are breastfeeding

People with diabetes or those who need to monitor their blood sugar

Few studies have examined the effects of intermittent fasting or long fasts on running performance. We do know that short overnight fasts can cause dizziness and weakness in runners. Over the long term, they may also lead to nutritional deficiencies that cause your body to burn muscle and leave you weaker.

Remember, no single nutrition/diet or weight-loss plan is suitable for all athletes. The best plan is one that meets your individual nutritional needs. It should be easy to maintain over a long period without depleting your body of the nutrients it needs to perform at its peak performance.